206 & 208

अब Quizwiz के साथ अपने होमवर्क और परीक्षाओं को एस करें!

the point of attachment over overhead premises wiring to a building shall in no case be less than ___ ft above finished grade

10

overhead feeder conductors shall have a minimum ____ ft vertical clearance over residental properties, driveways

12

a building disconnecting means that supplies only limited loads of a single branch circuit shall have a rating of not less than___

15 a

when performing thermographic surveys a major deficiency is indicated by a gradient of ____

16 degrees c

if a set of 120/240 v overhead feeder conductors terminates at a through the roof raceway or approved support, with no more than 6 ft of these conductors, 4ft horizontally, passing over the roof overhang, the minimum clearance above the roof for these conductors is not less than ____

18''

panelboards equipped with snap switches rated at 30a or less shall have overcurrent protection not exceeding

200A

the minimum clearance for overhead feeder conductors that pass over track rails of railroads is ___ ft

24.5

wires from a sensor to a ground fault relay should be no longer than ___

25 ft

conduits and raceways, including end fittings, shall not rise more than ______ in. above the bottom of a switchboard elcosure

3

grounded conductors _____ AWG or larger can be identified by distinctive white or gray markings at their terminations

4

an industrial plant using swithgear is most likely to require

480y/277v three phase four wire service

an insulated grounded conductor of _____ awg or smaller shall be identified by a continuous white or gray outer finish or by three continuous white or gray stripes

6

overhead feeders conductors installed over roofs shall have a vertical clearance of not less than ____ above the roof surface, unless otherwise permitted by an exception

8' 6''

the power in 3 phase wye connected circiuts can be calculated in three different ways

False

the continuous current that a circuit breaker can carry without exceeding a standard temperature rise is known as the ____

Rated current

underground raceways entering a ____ from outside shall be sealed

a or b

a self contained meter installation refers to ____

a single meter enclosure

The output of a generator may be connected_____

all of the above

article 200 provides the requirements for ____

all of these

the continuity of a grounded conductor shall not depend on a connnection to _____

any of these

where grounded conductors of different systems are installed in the same raceways, cable, or enclosure, each neutral conductor shall be identified to distinguish the systems by _____

any of these

panelboards supplied by a three phase 4 wire delta connected system shall have the phase with higher voltage to ground (high leg) connected to the ____ phase

b

raceways on exterior of buildings or other structures shall be arranged to drain and shall be____ for use in wet locations

b or c

overhead feeder and or branch circuit conductors shall not attached to a mast where the connection is ______

between

the nec requires that all grounding electrodes be ______

bonded

the two basic types of current transformers are the doughnut and the ___

busbar

equipment consisting of busbar mounted inside an enclosure that provides a means of tapping the service entrance conductors in called a ___

busway

field marking of service equipment shall include the )___

date fault current calculations performed

paneboard circuit directories can incude tables that depen on transient conditions of accupancy

false

when terminating conductors with mechanical lugs it is important to

follow manufacturer requirements

the screw shell of a luminaire or lampholder shall be connected to the _____

grounded conductor

the two to six disconnects for a disconnecting means for a building supplied by a feeder shall be

grouped

the conductor or busbar with a higher voltage to ground in a delta connection four wire system is known as ____

high leg

unused openings for circuit breakers and switches in switchboards and panelboards shall be closed using _____

identified closures

nonstandard abbreviations on electrical prints

legend

The three ____ are often represented by three vectors connecting the tips of the three winding voltages.

line votages

to provide flexibility in a commercial building before the number of tenants is known, the service should be terminated in a ___

main service disconnect

when installing multi family services the services disconnect ______

may be placed indoors under specific circumstances

nec article 376 contains definitions for

metal wireways

the purpose or use of panelboard circuits and circuit ______ inlcuding position, shall be legibly identified on a circuit directory located on the face or inside of the door of a panelboard, and at each switch or circuit breaker in a switchboard or switchgear

modifications

which of the following is a current transformer

oil filled

a building or structure shall be supplied by a maximum of ____ feeders or branch circuits

one

the disconnecting means for a building supplied by a feeder shall plainly indicate whether it is in the ____ position

open or closed

a panelboard shall be provided with physical means to prevent the installation of more _____ devices than that number for which the panelboard wsa designed, rated, and listed

overcurrent

a downed power line is most likely to result in a

phase failure

what provides a separation between the service drop conductors and other metal components

porcelain insulator attachments

where documented safe switching procedures are established and maintained and the installation is monitored by _____ indivuduials

qualified

the diconnecting means for a building supplied by a feeder shall be installed at a ___ location

readily accessible

the most important consideration for selecting a current transformer for relaying is the ___

saturation characteristics

plug in type back fed circuit breakers used to terminate field installed ungrounded supply conductors shall be _____ by an additional fastener that requires more than a pull to release

secured in place

connection diagrams should be used to

show the internal wiring connection between the parts that make up an apparatus

a panelboard shall be protected by an overcurrent device within the panelboard, or at any point on the ______ side of the panelboard

supply

a _____ can be used to help match the frequency of a generator to the busbar, or to match the frequencies of two generating units

synchroscope

the requirement for maintaining a 3 ft vertical clearance from the edge of the roof shall not apply to the final feeder conductor span where the conductors are attached to _____

the side of the building

for a delta connection, the winding voltages are equal to the line voltages

true

winding current is another term for phase current

true

the white conductor within a cable can be used for a _____ conductor

ungrounded

in swithboards, switchgear and panelboards, load terminals for field wiring, shall be so located that it is not necessary to reach across or beyond a ____ ungrounded bus in order to make connections

unisulated

receptacles shall have the terminal intended for connection to the grounded conductor identified by a metal or metal coating that is substantially ____ in color

white

the maximum 60hz voltage that can be applied to a switch for one minute without causing insulation failure is known as the ___

withstand rating

the three basic methods of sensing ground faults are ground return residual and

zero sequence


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